nbc's pete williams confirmed that at least one of them was spotted and is believed to be a pressure cooker-type bomb, a pressure cooker from your standard kitchen filled with some sort of powder and perhaps projectiles. at other times, they were described as having something like grenades or improvised explosives. i've seen some reports in the last few minutes that there are believed to be undetonated explosive devices in the watertown area. that's why they're trying to get people as far away as possible. >> chris, thank you very much. we'll have more from nbc news's chris palone in the program. a quick check off markets for you. global markets are taking these event necessary stride. we know very little still about the motives, about these suspects, beyond the fact that one has been skilled and the other is on the run and authorities are trying, of course, to resolve this situation there. we'll be right back. stay with us here on "worldwide exchange." >>> welcome to "worldwide exchange." a manhunt is under way from watertown, massachusetts, for suspect number two in the post bo mar